The present invention relates to a semiconductor imaging device. More particularly, the invention relates to a semiconductor imaging device composed of an array (one-dimensional arrangement) of pixels, each implemented with an SIT (Static Induction Transistor) having both light-detecting and switching capabilities.
The conventional semiconductor imaging device uses pixels having a separate light-detecting diode and switching transistor. With such a pixel, the output signal level and the device sensitivity are low. This low sensitivity of pixels puts a limit on the number of pixels that can be packed into the available area of the imaging device, hence limiting the resolution of the device.
The present inventors have previously disclosed semiconductor imaging devices that use an SIT as a light-detecting element. (See Japanese Patent Applications Nos. 204656/81 and 157693/82). In these devices, a light signal is stored in the gate region of the SIT, which has a high sensitivity to light, and a video signal is derived by controlling the current flowing between the source and drain according to the potential at the gate region. These devices are characterized by a high signal output.
One object of the present invention is to provide an improved semiconductor imaging device that produces a high signal output and whose output characteristics can be easily modified by purely electronic means.
Another object of the invention is to provide a semiconductor imaging device capable of producing optimum output characteristics irrespective of the imaged scene.